Elastic Properties of a Tungsten-Silver Composite Above and Below the Melting Point of Silver

摘要

The dynamic Young's modulus of a composite of tungsten containing twenty volume percent silver was evaluated up to 1020C. In the temperature range 25C to 800C, it was shown that the temperature dependence of the modulus as well as the absolute value of the modulus is closely approximated by the upper bound theory of Hashin and Shtrikman. Above 800C the modulus decreases much more rapidly than predicted by the theory. This rapid drop in modulus is believed to be associated with interphase boundary shearing between the tungsten and silver phases. A large discontinuity in modulus (over 10% change) is observed at the melting point of silver. Above the melting point of silver the modulus of the composite is about equal to the modulus of a tungsten sample containing an equivalent percentage of pores suggesting that there is no strengthening of tungsten from the presence of molten silver. (Author)